Kat (most commonly known as Mister Kat) is the main antagonist of the Canadian animated series "Kid vs. Kat". He is an alien cat who is sent to invade the earth and help his fellow cat-aliens take over the world. But after Millie Burtonburger, who is the younger sister of Coop Burtonburger, found him in the forest, she asks her dad Burt if she could keep him and he let him, only because she threw a fit about it.
He is definitely the WORST character in this show. He has done many sinful deeds to Coop, Dennis, and Fiona that make him downright unlikable.
He constantly tortures Coop by attacking him, harming him, framing him for stuff he himself (Kat) did and easily getting away with it scot-free, foiling Coop's plans, destroying evidence of his true colors just to make Coop look like a fool, and pretending to be an innocent cat to Millie.
He is just a generic villain who wants to help his pals take over the world, or even the universe.
He is infuriatingly painfully cunning, clever, and is easily quick to get away with almost anything that he has done instead of getting caught for once.
Whenever someone besides Coop and Dennis finds out about his true colors, he erases their minds so he won't get caught.
He can even get to be pretty scary sometimes. In "Tom-Kat Foolery", he makes a terrifying nightmare face after Coop pranks him while he was checking some plans. This could scare little children.
He was at his absolute worst in the series finale where he (as mentioned above in WHS#5) erases everyone's minds so nobody can know who he truly is and went back to fighting with Coop, so he basically won without getting full comeuppance or defeat.
Although he usually intends to get away with things, he sometimes gets his comeuppance, preventing him to become a Karma Houdini, but that isn't the best thing in the show.
His design is passable.
Despite being bad, Kat can be easily cunning although it's what makes him a bad character.
He and Millie share the same voice actress, who is no other than Kathleen Barr. This is very ironic since he is being trusted and spoiled by someone who shares his voice actress.